In the large-N limit, conditions for the conformal invariance of the g
eneralized Thirring model are derived, using two different approaches:
the background field method and the hamiltonian method based on an op
erator algebra, and the agreement between them is established. A free
field representation of the relevant algebra is presented, and the str
ucture of the stress tenser in terms of free fields (and free currents
) is studied in detail.